The invention relates to an optical unit for multiplying the frequency of a clock signal.
The invention also relates to a high-frequency carrier transmission system in which the receiver is provided with such an optical unit.
In systems operating with high-frequency signals, i.e. signals having a frequency of more than 10 GHz, there is the problem that the current electronic components are not rapid enough and are thus not satisfactory. 10 GHz may be considered to be an electronic barrier. Moreover, in many cases, these systems also comprise semiconductor lasers which can generally be modulated only to frequencies of 10-15 GHz maximum. Applications in which high-frequency signals are desired, which may also play an important role in future, are, for example, satellite transmission, optical telecommunication and mobile telephony.
In such systems, inter alia, high transmission rates are aimed at. To be able to detect data transmitted at high transmission rates, in other words data series having a relatively high modulation frequency, as faultlessly as possible, the repetition frequency of the clock signal should also be increased.